The definitions of the T categories correspond to the several stages accepted by FIGO.

TNM Categories/FIGO Stages

Primary tumor (T)

• TX: Primary tumor cannot be assessed
• T0: No evidence of primary tumor
• Tis/0: Carcinoma in situ
• T1/I: Cervical carcinoma confined to uterus (extension to corpus should be disregarded)
  • T1a/IA: Invasive carcinoma diagnosed only by microscopy. All macroscopically visible lesions—even with superficial invasion—are T1b/IB. Stromal invasion with a maximum depth of 5 mm measured from the base of the epithelium and a horizontal spread of 7 mm or less. Vascular space involvement, venous or lymphatic, does not affect classification
  • T1a1/Ia1: Measured stromal invasion 3 mm or less in depth and 7 mm or less in horizontal spread
  • T1a2/IA2: Measured stromal invasion 3 mm or more and 5 mm or less with a horizontal spread of 7 mm or less
  • T1b/IB: Clinically visible lesion confined to the cervix or microscopic lesion larger than T1a/IA2
  • T1b1/IB1: Clinically visible lesion 4 cm or smaller in greatest dimension
  • T1b2/IB2: Clinically visible lesion 4 cm or larger in dimension
• T2/II: Cervical carcinoma invades beyond the uterus but not to the pelvic wall or to the lower third of the vagina
  • T2a/IIA: Tumor without parametrial involvement
  • T2b/IIB: Tumor with parametrial involvement
• T3/III: Tumor extends to the pelvic wall, and/or involves the lower third of the vagina, and/or causes hydronephrosis or nonfunctioning kidney
  • T3a/IIIA: Tumor involves the lower third of the vagina and does not extend to the pelvic wall
  • T3b/IIIB: Tumor extends to the pelvic wall and/or causes hydronephrosis or nonfunctioning kidney
• T4/IVA: Tumor invades mucosa of the bladder or rectum and/or extends beyond the true pelvis (bullous edema is not sufficient to classify a tumor as T4)

Regional lymph nodes (N)

• NX: Regional lymph nodes cannot be assessed
• N0: No regional lymph node metastasis
• N1: Regional lymph node metastasis

Distant metastasis (M)

• MX: Distant metastasis cannot be assessed
• M0: No distant metastasis
• M1/IVB: Distant metastasis